Mexican trouts - the need for status surveys and research

1. Mexican trouts - the need for status surveys and research Dean A. Hendrickson-Univ. Texas, Austin Lloyd T. Findley-CIAD, Guaymas Héctor Espinosa Pérez-IBUNAM

2. Sierra Madre Occidental • Sonora, Chihuahua, Durango • Rios Yaqui, Guzman, Mayo, Fuerte, Sinaloa, Culiacan, San Lorenzo, Presidio (from Behnke. 1992. Native Trout of Western North America)

3. History Needham and Gard 1936-37 Baja California 1952 Durango - Needham, Lattin, Weitzmann & Solorzano - Rios San Lorenzo & Presidio

4. History 1953 - Flechsig & Moller - Rios Culiacán, Sinaloa, Fuerte (Verde) - Guadalupe y Calvo area 1955 - Needham & Rupp - Yaqui and Guzmán

5. History 1948 - A.S. Leopold - Yaqui (single collection) 1960’s - R.R. Miller et al. - Yaqui, Mayo (various collections) 1975 - C.H. Lowe, L.T. Findley, D.W. Owens, et al. - Mayo & Yaqui (various collections)

6. History 1978 - Hendrickson, W.L. Minckley et al. - Yaqui (10 sites) & Mayo. First specimen of rainbow trout in Yaqui in México, though trout culture had clearly existed in the basin for many years before.

7. 1980’s - 1997 - Hendrickson, Findley, Espinosa, Mayden, Tomelleri, Kuhajda, Nielsen, Jensen, and others. Various expeditions.

8. What do we know? • O. chrysogaster (Mexican golden trout) is sister to rest of genus • Yaqui / Mayo / Guzmán forms undescribed • Yaqui / Mayo / Guzman genetically distinctive from other species • Guzmán apparently same as Yaqui (Bavispe) • Some evidence for N & S Yaqui forms (S form shared with Mayo • MANY questions remain • MANY threats

9. Logging

10. Logging • stream sterilizations due to sawdust as early as 1930’s • A. S. Leopold - logging and other (e.g. predator removal) impacts • Early 1990’s mega-scale logging infrastructure project proposed (World Bank funding). Impact studies began, none directly related to aquatic systems. Project fell through after several years, apparently due to economic issues. • Road building continues, increasing access and human population pressures in formerly remote areas. Tourism following access. • Milling and other lumber processing often done in remote areas with apparently little regard for impacts.

11. Bosque Modelo Sustainable forestry development Canadian international network • Improve forest future through improved management • Biodiversity conservation • Create alternatives to employment in logging industry • Environmental education • New technologies for natural resource research & management

12. General coordination (21%) • Ecotourism (?%) • Extensionand promotion (15%) • Pollution control (5%) • Nursery / reforestation (9%) • Geographic Info. System (13%) • Trout culture (7%) • Agricultural improvements (5%) • Tree farming (12%) • Wildlife (T&E birds) (3%) • Chihuahuan spruce protection and forestry promotion (11%) Bosque Modelo

13. Bosque Modelo • Calabazas - Ejido San Juanito • El Aparique - Ejido El Ranchito • Trainingof ejiditarios • Production & Marketing - both very successful • Promotion & support - “during this year we have seen private initiatives and tank construction throughout the region” • Before/After impact monitoring“there are absolutely no problems originating from operation of hatcheries” • Future - “involving ejiditarios in all aspects from start to finish guarantees that all aspects of this technology will be perfectly adopted by the local community”

14. Promotion Bella trucha nativa y única de tu región, el aparique, en peligro de extinción, ofrece alimenticia gratis, apoya turismo y es buen indicador de salud de tu ambiente general. Cuidala y no la amenaza por cultivar la trucha arco iris.

15. Current status? Guzman system • Río Escalariado - tiny, recently logged, very small population, future very uncertain • Río Seco (Needman and Gard) - ¿Seco? Needs additional exploration. • One other population known.

16. Current status? Yaqui / Mayo systems • No comprehensive survey since 1978, and that was mostly focused on lower elevations of Yaqui only. Tributary Río Negro • Rainbows have long been in culture. Hybrids not yet documented. • Trout culture and logging rapidly expanding, fires have been recently severe.

17. Current status? Many habitats are highly degraded, erosive, and incised into beds with little shading provided by riparian. Trout are absent from probable historic mid-elevation habitats and some high-elevation historic localities. The recent first drying of Cascada Basaseachic in recorded history is probably related to poor drainage management. Re-invasion after extirpation is often not possible. Cascada Basaseachic

18. Current status? Small scale rainbow trout grow-out operations are rapidly becoming commonplace, even in very remote areas. And are highly susceptible to escapes. Tributary Río Candameña

19. Current status? Native trouts are often found only in uppermost, tiny headwater streams. And are absent from historic habitat in larger streams. Tributary Río Candameña (Mayo) Río Verde (Fuerte)

20. Current status? Or, they persist in highly degraded habitats where rainbows probably couldn’t survive (e.g. Agua Blanca, Río Culiacán).

21. Recommendations • Status surveys throughout Sierra Madre Occidental including Rios San Lorenzo and Presidio • Further genetic studies (with vouchering of specimens in major collections) • Habitat assessment and requirements studies • Public education • Coordination with fish culture industry and government agencies • Protected Areas • Ecotourism (e.g. fly fishing)

22. Paul R. Needham’s Trail of the Mexican trout (1955, Pacific Discovery VIII(4):18-24) ends with “Maybe … in 1936, a new era was started when trout will be freely exchanged between the sister Republics to the mutual benefit of each.”